What are the “telling details” of a piece of media?

Small details that give a lot of information in a short amount of time.

Explanation:

"Telling details" are the details that inform us of what the piece is trying to convey. Telling details are usually very specific, and they allow us to "see" what the writer is describing and understand a lot of information quickly. In the case of media, it is usually a word, phrase or image that allows us to understand the message being conveyed. These details are precise, illuminating and descriptive.

1. c- the tunnel project was worthwhile.

2. b- to inform about the value of the tunnel project